pg-gin-strange-initialization2.diff

#
# Minor cleanup of ginInsertValue with additional asserts and
# a tighter loop for finding the root in the GinBtreeStack.
#
============================================================
*** src/backend/access/gin/ginbtree.c	2d3e63387737b4034fc25ca3cb128d9ac57f4f01
--- src/backend/access/gin/ginbtree.c	f6dc88ae5716275e62a6f6715aa7204abd430089
*************** ginInsertValue(GinBtree btree, GinBtreeS
*** 276,294 ****
  ginInsertValue(GinBtree btree, GinBtreeStack *stack, GinStatsData *buildStats)
  {
  	GinBtreeStack *parent = stack;
! 	BlockNumber rootBlkno = InvalidBuffer;
  	Page		page,
  				rpage,
  				lpage;
  
! 	/* remember root BlockNumber */
! 	while (parent)
! 	{
! 		rootBlkno = parent->blkno;
  		parent = parent->parent;
- 	}
  
! 	while (stack)
  	{
  		XLogRecData *rdata;
  		BlockNumber savedRightLink;
--- 276,296 ----
  ginInsertValue(GinBtree btree, GinBtreeStack *stack, GinStatsData *buildStats)
  {
  	GinBtreeStack *parent = stack;
! 	BlockNumber rootBlkno;
  	Page		page,
  				rpage,
  				lpage;
  
! 	/* extract root BlockNumber from stack */
! 	Assert(stack != NULL);
! 	parent = stack;
! 	while (parent->parent)
  		parent = parent->parent;
  
! 	rootBlkno = parent->blkno;
! 	Assert(BlockNumberIsValid(rootBlkno));
! 
! 	for (;;)
  	{
  		XLogRecData *rdata;
  		BlockNumber savedRightLink;
*************** ginInsertValue(GinBtree btree, GinBtreeS
*** 469,474 ****
--- 471,477 ----
  
  		UnlockReleaseBuffer(stack->buffer);
  		pfree(stack);
+ 		Assert(parent != NULL);		/* parent == NULL case is handled above */
  		stack = parent;
  	}
  }